Posts Tagged ‘Cordulegaster maculata’

New Life List additions in 2018 (odonates)

December 28, 2018

The anticipation of the hunt and the thrill of discovery — the adrenalin rush from finding the target species is ever more elusive as one gains experience and expertise. Accordingly, the number of additions to my Life List is fewer year after year.

Editor’s Note: List items are presented in chronological order, based upon the date of the spotting.

Twin-spotted Spiketail

A Twin-spotted Spiketail dragonfly (Cordulegaster maculata) was spotted at Occoquan Regional Park, Fairfax County, Virginia USA. This individual is a male.

Brown Spiketail (male)

A Brown Spiketail dragonfly (Cordulegaster bilineata) was spotted at Occoquan Regional Park, Fairfax County, Virginia USA. I saw a female Brown Spiketail on 09 May 2013. This individual is one of several males that I spotted on 07 and 11 May 2018.

Gray Petaltail

Gray Petaltail dragonfly (Tachopteryx thoreyi) was spotted at a forest seep. This individual is a male with a malformed abdomen that I nicknamed “Bender.”

06 JUN 2018 | Northern Virginia | Gray Petaltail (male)

Sable Clubtail

Sable Clubtail dragonfly (Stenogomphurus rogersi) was spotted perched near a small stream located in Fairfax County, Virginia USA. This individual is a male.

08 JUN 2018 | Fairfax County, VA | Sable Clubtail (male)

Citrine Forktail damselfly (male)

Citrine Forktail damselfly (Ischnura hastata) was spotted during a stream-walk along South Fork Quantico Creek in Prince William Forest Park (PWFP), Prince William County, Virginia USA. This individual is a male.


Next post: Recognition in 2018.

Copyright © 2018 Walter Sanford. All rights reserved.

Twin-spotted Spiketail (male claspers)

May 17, 2018

All male dragonflies have three terminal appendages, collectively called “claspers,” that are used to grab and hold female dragonflies during mating: an upper pair of cerci (“superior appendages”) and a lower unpaired epiproct (“inferior appendage”).

Male members of the Family Cordulegastridae (Spiketails), including male Twin-spotted Spiketail dragonflies (Cordulegaster maculata), have relatively small cerci (terminal appendages) that can be mistaken for female cerci.

Male dragonfly secondary genitalia, called hamules, are located below abdominal segments two and three (S2 and S3), as shown in the following annotated image. Hamules come in a variety of sizes and shapes, but their function is identical for all species of odonates.

Related Resources

Copyright © 2018 Walter Sanford. All rights reserved.

Twin-spotted Spiketail dragonfly (male)

May 9, 2018

A Twin-spotted Spiketail dragonfly (Cordulegaster maculata) was spotted at Occoquan Regional Park in Fairfax County, Virginia USA. This individual is a male, as indicated by his terminal appendages and “indented” hind wings.

Those who know me well are familiar with one of many “Walterisms”: “I haven’t ‘seen’ something until I have photographed it.” My rationale is two-fold: 1) A photograph verifies a sighting. 2) The detail visible in a good photograph exceeds the acuity of the human eye.

Although I’m fairly certain I’ve seen a Twin-spotted Spiketail at another location, this is the first time I was fortunate to photograph the species. Twin-spotted Spiketail is relatively uncommon in Northern Virginia.

The last two photos show what might be the same male shown in the first two photos, but it might be another male. As Mike Powell and I were photographing the first male, another dragonfly swooped in and there was either a brief aerial ballet or battle, depending upon whether the second dragonfly was a female or male. I visually tracked the first dragonfly to a new perch about 10 feet away.

When I started to move toward the new perch, Mike shouted “Don’t move, don’t move!” Mike had spotted another Twin-spotted Spiketail that landed close to the place where I spotted the first one.

We didn’t have much time to shoot photos. This Twin-spotted Spiketail and another one hooked up and they flew in wheel toward the nearby treetops. The mating process for Twin-spotted Spiketails lasts about an hour, a fact that may explain why we never saw another Twin-spotted during our photowalk.

Related Resources: Digital Dragonflies, presenting high-resolution digital scans of living dragonflies.

  • Genus Cordulegaster | Cordulegaster maculata | Twin-spotted Spiketail | male | top view
  • Genus Cordulegaster | Cordulegaster maculata | Twin-spotted Spiketail | male | side view
  • Genus Cordulegaster | Cordulegaster maculata | Twin-spotted Spiketail | female | top view
  • Genus Cordulegaster | Cordulegaster maculata | Twin-spotted Spiketail | female | side view

Copyright © 2018 Walter Sanford. All rights reserved.


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